Ice cream freezer for refrigerators



May 7, 1.935. c. 1'. HOFFMAN ICE CREAM FREEZER FOR REFRIGERATORS 4 Sheets-Sheet 1 Filed July 11, 1932 Big. lv.

.m W. a W

y 1935- c. -r. HOFFMAN 2,000,023

ICE CREAM FREEZER FOR REFRIGERATORS FiledrJuly 11, 1932 4 Sheets-Sheet 2 May 7, 1935. c, 'r HOFFMAN 2,000,023

ICE CREAM FREEZER FOR REFRIGERATORS Filed JuIy 11, 1932 4 Sheets-Sheet 3 1935- Y c. T. HOFFMAN Q 2,000,023

ICE CREAM FREEZER FOR REFRIGERATORS 4 Filed July 11, 1932 4 Sheets-Sheet 4 lcefcksnm 0 FREEZERUV o up w. -/I.C.

UNITED STATE ICE CREAM FREEZER FOR. REFRIGERATOR/S Charles '1. Hoffman, Washington, D. (3., assignor, by direct and mesne assignments, to Emory L.

Grofl, as trustee Application July 11, 1932, Serial No. 621,988

itself to the type of face plates of standard- 1 evaporator units; that is, face plates of the generai form and dimensions of those now generally in use. In that connection the invention contemplates the provision of separate electromagnets so arranged as to be readily fitted to the 16 standard type face plate at any desired location thereon with reference to the ice pan emplacements, thereby readily to permit the use of an ice cream'freezing pan equipped with pole pieces and a rotor, which pole pieces constitute in effect a continuation of the electromagnets for purpose of furnishing electromotive. power to the rotor with the use of commercial alternating current in the coils. The arrangement set forth also provides for readily utilizing the space on the face plate above the ice pan emplacements for the ice cream freezer control as well as the controls for modifying the operation of the reir s t s a pa Another and distinctive obiect'is to provide a combination ice cream freezer control switch and adjustable cold control means which simplifies the operation in the respect that the mere-act of turning the ice cream freezer'control :on also operates the means for obtaining increasedcold at the evaporator. That is to say, when the cold control knob or button is turned to produce increased cold conditions in "the refrigerator, the ice cream freezer circuit will be automatically closed. a Another obiect is to provide means to assis i isnetic rotor to assume synchronous speed i manual launching thereof without the need for a specially provided friction-inertia memher. That is to say, in the present invention the 4 functions usually performed by such element are performed by the dasher means o'peratively conwith the rotor, together with an intervenin: gear-train, whereby there is obtained the neoessary inertia or balancing effect for assisting the rotor when manually launched, to settle into step with the magnetomotive pulsations produced by commercial alternating current in the electromagnets when such launching is terminated out of step with said pulsations.

A further object is to provide dashers which (01. sa-nc) may be readily removed and reinserted in operative position in the container for freezing the mixture.

A still further object is to provide a special pan construction having particularly in view a 6 scraping action as well as agitating and stirring action, whereby corner pockets will be avoided and all of the contents of the pan will be readily agitated and stirred. As will-be more apparent as the invention is better understood, the dasher elements cooperate with the specially formed pan bottom and sides so that the material scraped andimpelled by one dasher will be thrown into the path of operation of the other dasher thereby adequately to agitate and stir; the mixture.

A preferred and practical embodiment of the invention is shown in the accompanying drawings in which:--

Figure 1 is a detail view of a portion of a mechanical refrigerator with parts broken away to illustrate the application of the invention.

Figure 2 is an enlarged detail view illustrating the motor assembly and freezing pan disa'ssociated from the face plate.

Figure 3 is a top plan view of the construction shown in Figure 2.

Figure 4 is a detail cross sectional view takenon the line 44 of Figure 3.

Figure 5 is a diagrammatic view illustrating the electric circuit, as well as the electromagnetic pole pieces which engage with the detachable f pole pieces on the freezing pan.

Figure 6 is a vertical cross sectional view taken on the line 6-6 of Figure '7.

Figure 7 is a. horizontal sectional view taken on the line 1-1 of Figure 6. 4

Figure 8 is a diagrammatic view of a mechanical refrigerator showing the embodiment of the invention which contemplates the combination of the ice cream freezer switch with the cold control means. I

Figure 9 is a diagrammatic view illustrating the mechanical manual control elements constituting the cold control switch and the ice cream. freezer switch and the circuits involved.

Figure 10 is a detail vertical sectional view taken on the line illof Figure 9.

Figure 11 is a detail view of the circuit closing element in the combined ice cream freezer switch andcold control switch.

Figure 12 is a detail view of the face plate or switch panel of the refrigerator controls used in the present invention.

Similar reference characters designate correthe drawings.

In the embodiment shown in the drawings, the usual refrigerator cabinet is designated generally as A, the same being provided with the door B for closing the cooling compartment C. The latter has mounted therein the usual evaporator or cooiing unit D covered by the typical front piece or face plate E. In accordance with the usual practice, the evaporator is provided with one or more 1 ice pans G fitting into suitable compartments,-

one of which maybe used to receive the ice cream freezer which is in the form of a pan generally conforming to the characteristics of an ice pan. The ice cream freezer, including the rotor, divided pole pieces, and pan, is designated generally as H and is shown in the upper compartment of the evaporator. It will, of course, be understood that when it is not desired to make ice cream, this compartment may be fitted with one of the standard ice pans G. However, when it is desired to make ice cream, the freezing mixture is simply placed in the pan of the ice cream freezer and the entire unit slipped into place in the evaporator compartment whereupon portions of the motor carried by the pan contact with suitable pole pieces so that when the current is supplied to induce electromagnetism at the pole pieces the motor will proceed to function in the manner hereinafter described more in detail.

In the illustration of Figure 1 it will be observed that the face plate E is provided with an ice cream freezer switch device designated generally as S and may also be provided with the cold control knob or handle M and thedefrosting and indicator switch N. In Figure 1 the ice cream freezer control switch is shown as bein on the same panel or plate E with the knob M and indicator N but disas'sociated in a mechanical and electrical sense. However, the present invention contemplates not only the feature of locating all of these elements on the same plate or panel within the cooling compartment, namely, on the face plate 'of the evaporator, but also to interconnect and consolidate the ice cream freezer switch and cold control means so that they function together. under one manual operation, as shown in Figure 9.

- ceptacle. If the eleetromagnets l-! are energized by alternating current with theice cream freezer H and its associated pole pieces 5- and rotor 50 removed from such receptacle, the pulsating magnetic flux will proceed from pole to pole of the electromagnets acrossa path of substantially maximum reluctance. The pathfor the magnetic flux under this condition is an air path or its equivalent and therefore a path of.

maximum reluctance to the extension of the magnetic fiux, inasmuch as all parts of the evaporator under the proposed construction are of non-magnetic metal or material, and it is well known that non-magnetic metals or materials offer the same reluctance to electromagnetism as air. 'Ihus it.wiil be apparent .that when the ice cream freezer H is inserted in the receptacle at theevaporator D, with the pole pieces i-l and rotor is of magnetic metal disposedbetween the poles 3-3 of the electromagnets, the reluctance of the path tothe extension of the magnetic flux sponding parts throughout the several fi ures of from pole to pole will be reduced, and it is the purpose of this invention to utilize this principle of reducing the reluctance to the path of the magnetic fiux from pole to pole of the electromagnets to lead the pulsating magnetic fiux to 1 an effective location to operate by a magnetic rotor of a synchronous motor agitating and stirring means ina liquid container when such container isinsertedin the receptacle ofthe evap-' orator. i

Referring now more in detail to the features of construction involved (Figures 1 and 2), particularly with reference to the motor assembly for actuatingthe dasher means of the ice cream freezer- H, it will be observed that the rear face of the face plate E is provided with electromagnets l' and 2, the same being provided with the pole pieces 3-3, which may be secured to. the face plate by suitable fastenings 4 so that the beveled faces 30 of the pole pieces will lie in the path of the pole pieces 5-! carried by the pan P of the ice cream freezer. These electromagnetic polepieces may be readily fitted to the inside face of any standard shaped face plate, which is preferably made of non-magnetic material. In the arrangement shown the pole pieces are so disposed as to cooperate with the upper pan compartment or receptacle of the evaporator. It is obvious, however, from the nature of the construction that they may be .installed at the location of any of the pan compartments depending-upon the selectivecholce of the user of the refrigerator.

At this point it may be noted with reference to the electromagnets I and 2 that the pole pieces 3-3 thereof adapted to contact with the pole pieces H carried by the pan P must be simultaneously of opposite polarity at each half cycle of each alternation of the alternating current applied thereto-in order that said pole pieces 3-3 will attract each other through'the pole pieces 5-! when the ice cream freezer is placed in operative position in the selected evaporator compartment. The preferred method of accom-' plishing thisresult is to wind both coils of the electromagnets .in the same direction, as indicated by the arrows in Figure 5, and so lead the current to the coils that the flow of current at each half cycle of alternation will be in the opposite direction through onecoil from that in the other. By connecting the coils in series, as

shown in Figure 5, and by having the coils wound in the same direction, the pole pieces 3-3 will always be of opposite polarity, that ladle of said poles will be "north at the same time the other is "south, and viceversa, upon each half cycle of alternation of the alternating current.

The pole pieces 3-! carried by the P'of the ice cream freezer are preferably carried ,by a

suitable frame or housing 8, which is'in turn carried by the pan P andserves not only use. support for the pole pieces 3-! but also as a housing for the gearing designated generally as 1 for operating the dashers 3. It will, of course,

a manual launching knob II. From this. ar rangement it will be apparent that the of the rotor la may readily be effected by turning the knob or handle it of the shaft I in either direction, since the movement imparted by, this action will be transmitted to all of the gearing which is directly connected with the rotor.

In connection with the launching of the rotor Is, it will, of course, be imderstood. as outlined by the obiects of the invention, that no frictioninertia member is necessary dueto two features; first, that there is suiiicient looseness or pla'y in the teeth of the gearing-to assist the' rotor in balancing itself into step with the pulsation of the magnetic flux, and, second, because of the novel dasher means which also serve to balance the action of the rotor into step with the pulsa- ,tions of the magnetic ilux projected across ti ie rotor when the ice cream freezer is inoperative position and alternating current is applied to the coils of the electromagnets I and Q. I have discovered that the looseness or play in the 'gear teeth and the novel dasher means employed',' 'or either of these constructional features, prod to the desirable balancing effect upon the r r when manually launched to cause said rotor promptly to assume a steady speed in synchronisin with the pulsating flux pro uce at; th poles of the elctromagnets. 'I'hajt to, say, ,while both of these features may be present in actual construction, either one oi them has bgl i foi ind sumcient in practical use to produce tlielriece'ssary eiiect with reference to theof the rotor into step with the ,fluxpuliiatipns.

- and any tendency of the rotor hunt is completely eliminated. I have also-discovered that,

' inasmuch as the magnetic torque on lthejrotor at the time of manual laimchiiig is greatly in excess of the useful as well as thefrictional-load,

due to the provision for power torque tin-the th f tor to meet the greatly inereasediood yhi curs when the freezing mixture advances congealment, such excess magnetic torque on' the rotor has vital influence on the with which the rotor may be launched manually with the immediate assumption by the rotor of synchronous speed in step with the flux pulsations.

In connection with the novel designated generally, as I, it will be observed that the dasher or paddle elements proper-are. designated generally as to and are: provided with the central shaft portion lb, one end or which is provided with a socket lc for receiving a supporting spindle II. This spindle is preferably slidably mounted in a suitable sleeve provided on the pan and is-formed at its outer end with an interiolly threaded nut portion i2 toengage with j8, mating exterior of sleeve. 0 By rotating the nut 12 the spindle may be shifted in either direction longitudinally iii-.the'

sleeve to engage in the socket lo and thus lock theidasher in place, the opposite-end, of the dasher having a novel key arrangement for. connecting with the gear shafts, as. will presently appear. This arrangement also provides a fluid tight bearing for one end of the dasher shaft. .The opposite end of th'edasher shaft is provided with a k y I adapted to be placed in i 810); w

formed in the end of one of the shafts tvhich form a part of the gear train I. As will be observed from the drawings, the keys I! have a. relatively loose nt in the slots I! so that relative play is permitted to a certain extentbetween the dasher shaft and the shafts with which the em.

are connected. the;.teeth of the gears me stituting the gear. train fit relatively close, it has been found that the play aflorded by the key and slot arrangement lI-ll will be suflicient to thereby to permit themixture to freeze hard in the usual manner. Furthermore. the detachability of the dashers renders the cleani g of the pan is simple and practical operation. In installing the dashers in, the pan it is only necessary toslip the key it in the slot It and then live the spindle H into the socket lc by manipatinggthe nut or knob I! to insure locking of the dasher properly in place.

modified ty'p'e of pan as well as a modified of-dasherjisshown in mes 6 and 7.

. thesefigures it will be observed that the P is i'oi-me i' with a; novel bottom portion which is .phiticularly designedto avoid pockets attire corners of the pan sothat all of the mix exists; in the scraping action accomplished by.

dashe blades with reference to the rounded i! of. the pan. As will be apparent from i the. dasher elements iS-JI operate in" the same directions so that the mixture thrown .to be;;. frqzien will be subject to the action of; the dashers. As will be observed from Fig- 03 fromone dasher will be moved over into the I P h the other dasher, thereby assisting in the -formi'ition of a complete circuit for the mixture heing'frozen.v While action is also present with the dasher'arrangement shown inl 'igures 3 and}, nevertheless the rounded formation at the bottom corners of the pan together with the arched central formation shown in Figures 6 ani'i'i. contribute to a thorough mixing of-,the; orcontents', of the pan, :8

as cutting the during the freezing Referring further to the means for controlling the circuit to the electromagnets, it has been previously explained that the electric circuit arramiment. shown' in 5 includes the ice cream freezer switch 8. when the handle or knob bf the switchis turned to the "011 positionit wilibe apparent that the circuit is closed tothemagrietaaiidwhenthe handle ofthe switch is turned to the "OE" position the circuit will b'ebrokeh. same result may be accomplished with the arrangementshown and described in Figures I to 12 inclusive, with the added advantage that when the cold control means is turned to produce the lowest pomble temperatures necessary to freeze mixtures of freezer motor will be automatically turned on.

Figure 8 illustrates atically a standard type refrigerator equipped with the evaporator, compressor, condenser, and motor for operating the compressor, including necessary auxiliary valves for maintaining a proper flow of a refrigerant element to produce at the evaporator the necessary cold conditions to refrigerate the cooling compartment by the removal of heat therefrom, and also thermal means for maintaining the evaporator within predetermined temperature limits, which thermal means is adjustable to obtain at the will of the user lower temperatures by the manually adjustable selective settings of said thermal means. The refrigerator thus illustrated contemplates a compressor having a capacity, in conjunction with relative large capacity of the associated refrigerating elements and mechanism, to produce cold conditions at the evaporator greatly in excess of that required to maintain the cooling compartment at the proper temperature at the slowest freezing speed of the apparatus. That is to say, the capacity of the compressor and auxiliary refrigerating equipment is such that at normal operation the compressor operates only a fraction of the time, whereas when increased cold conditions are desired at the evaporator the compressor may be caused to operate for a greater portion of any period of time taken as an example. Whether the compressor operates to produce refrigeration during a minimum active cycle or the maximum active cycle or any intermediate degree of activity depends upon the setting of the manually adjustable temperature control means.

Thus, the invention contemplates the provision of means for rendering the ice cream freezer operative simultaneously with the bringing into play of the means for modifying the operation of the means for maintaining the evaporator within predetermined temperature limits to produce subnormal cold conditions at the evaporator necessary to freeze heavy cream mixtures.

Referring to Figure 8, as previously indicated, the face plate E of the evaporator is provided with the defrosting switch N, which, as will be observed from Figure 9, is included in the motor electric circuit and has the "On" and Off positions indicated in the latter figure. When it is desired to defrost the ice forming unit in the cooling compartment of the refrigerator, the switch including the knob N is turned to the "01?- position, but when the refrigerator is in normal, use the switch N'N2-N2 remains in the On position.

The contact for the On" position is designated as 22 and carried by an insulated block 2| mounted in the housing 22 and which latter is .in turn provided with an insulating cover 22. This cover is secured to the face plate E by screws or equivalent fastenings and in additionto carrying the temperature selector designated generally as M, as will bepresently described. permits the handle br shaft N2 which carries the knob N of the switch to project through the same for the purpose of manipulation.

The arm N2 of the switch N'N2N2 is electhe motor Y with power, the other side of the circuit being indicated by the line 25. when the arm N2 isin engagement with the. contact 22, current will pass to the motor Y as follows:

first, over the line 2241 which is connected to a metallic arcuate contact member 22 slida'bly mounted in the sleeve 22a carried by the bracket 22b fixed on the insulating cover 22, and thence to the metal arm 21 which is a part of the thermostat T. This metal arm 21- is mounted on a .by the wire 21a with the motor Y. And, as previously indicated, since the motor is connected with the return wire 22, it will be apparent that the motor will operate under normal conditions when the arcuate contact 22 and the arm 21 are in engagement. In other words, each time the box warms up to the predetermined degree, the contacts 20 and 21 come together and close the motor circuit so long as the switch arm N2 is engaged with the contact 22. This is descriptive of normal box operation, that is, operation of the refrigerator without stepping up the coldcontrol means. when it is desired to obtain increased cold conditions at the evaporator the knob or equivalent member M may be turned counterclockwise from the position "1 on Figure 12 to any selected station or position regardless of whether the ice cream freezer is in use or not. This is accomplished through the turning of the knob M connected by the shaft 21 with the insulated cam 22 which is engaged continuously by the arcuate arm 28 due to the spring 220. Thus by adjusting the knob M any degree of cold can be selected at will. This type of cold control means is shown by way of example, to illustrate how selective cold conditions can be obtained within any desired limits, and it will, of course, be understood that its equivalent may be used in conjunction with the feature of automatically -tuming on the ice cream freezer at a stage of cold selection, without departing from the inven- I are included in a shunt circuit 20 which is connected as at 2i with the return line 25 and also connected as at 22 with a contact arm 22 mounted on the insulating block 2|. Adjacent to the contact arm 22 is another contact arm 22 which is connected by the wire 24 with the line wire 22.

when it is desired to obtain increased cold conditions at the evaporator and simultaneously connect the shunt circuit 22 of the ice cream freezer with the main'lines 24 and 25, it is only necessary to rotate the temperature selector knob M, whose shaft 21 carries the insulated cam 22 previously mentioned, to its maximum counterclockwise position. This cam is provided with a circuit closing member or blade 22 adapted to bridge the contacts 22 and 24 when the knob M is rotated suiilciently, in the direction set forth, to bring the'blade 22 into the dotted line position shown in Figure 9. The effect of moving the knob 26 to close the shimt circuit 22 to the ice cream freezer motor is to also rotate the cam 22 thereby to move the arcuate contact member 26 against the tension of the spring 26a so as to move the end of the contact 22 which engages the arm 21 further toward the left in Figure 9 to effects. lower temperature setting. By moving the arcuate contact 26 and the arm 21 further toward the left it will be apparent that the circuit 12 so that the pointer on the knob or handle M to the motor Y will be maintained closed over the same path as previously described, for a' evaporator, it will be apparent that the thermostat element 29 will move the arm 21 away from the end of the arm 26 and temporarily break the motor circuit until the temperature of the box again rises to a point where it is necessary to restore the motor circuit. This intermittent action of the motor under the influence of the temperature selector elements produce prolonged periods of active mechanical cycles thereby, to

maintain increased or lowered cold conditions to effect freezing of the mixture in the ice cream freezer.

From the foregoing it will be understood that the closing of the shunt circuit 30 m ne ice cream freezer motor will simultaneously and automatically adjust the thermostat T to effect increased cold conditions at the evaporator. When it is desired to turn the ice cream freezer circuit off, it is only necessary to turn the knob M clockwise away from the On position which appears on the face plate 23 as shown in Figure invention provides not only convenient means forassembling the electromagnets with reference to the ice cream freezer pan location, but also through the use of the novel pan and dasher elements 1 rmi f th mixing.

disc osed De ts o orough carried by said pan, and said" pole pieces being of the contents of the pan, while, at the same time, when the mixture has reached the proper stage of congealment the dashers may be readily removed by lifting them out of the pan so that the latter may be placed back in the evaporator compartment for hardening. Also by reason of the single control provided for the temperature selector means and the ice cream freezer switch the mere act of operating a single control permits the user to start the freezer in operationand at the same time avoids omission to properly set the temperature selector to produce increased cold conditions necessary to freeze ice cream mixtures by the mere act of turning the ice cream .freezer on. With this arrangement there is no possibility of the user of the refrigerator being disappointed in obtaining a frozen mixture, as might be the case where the changing of the temperature selector might be overlooked when the icecreammixtureisinsertedandthefreezer turned on by separate means.

It will, of course, be understood that the cores of the electromagnets l-2 are of laminated magneticmetal, as are also the pole pieces H and rotor la. This metal will be subjected to intense moisture conditions in use, and if such metal is the usual iron or steel used in the construction of motor parts of this character it will rust. Busting may be prevented by having this metal nickeled or chromium plated. The preferred method of preventing the rusting or corrosion of the laminated portions of the motor, however, is

to use in their construction what is commercially a rmtproof.

Without further description, it is thought that the several features and advantages of the inventionwill be readily apparent, and it will, of course, be understood that changes in form, proportion, and details of construction may be resorted to without departing from the scope of the appended claims. v

I claim:

1. In a refrigerator having an evaporator provided with pan compartments, a face plate for the evaporator, electromagnets fitted to the face plate at a pan compartment location of the evaporator, a pan for the mixture to be frozen adapted to be inserted in one of said compartments, a rotor and divided pole pieces carried by said pan, said pole pieces being adapted to contact with the electromagnets.

2. In a refrigerator having an evaporator provided with pan compartments, a face plate for the evaporator, separate electromagnets fitted to the face plate at'each side of a pan compartment location of the evaporator, a pan for the mixture to be frozen adapted to be inserted in one of said compartments, a rotor and divided pole pieces carried by said pan, said divided pole pieces be-- ing magnetically coupled with the electromagnets.

3. In a refrigerator, an evaporator provided with pan compartments, a face plate for the evaporator having a control panel portion and an opening for permitting access to said compartments, electromagnets fitted at each side of said ,opening at the location of a compartment and clear of the said control panel portion thereof, a circuit including said electromagnets, a switch also in said circuit and mounted on the panel portion of the face plate, apan for the mixture to be frozen adapted to be inserted in one of said compartments, a rotor and divided pole pieces magnetically coupled with the electromagnets.

4. In a refrigerator, an evaporator having pan compartments, a face plate adjacent the end'of said compartments, electromagnets carried by the face plate and provided with pole pieces, a pan insertible in one .of said compartments, a rotor and pole pieces carried by the pan, said latter pole pieces being adapted to engage with the pole pieces of the electromagnets, and inertia means for the rotor comprising dasher elements operatively connected with the rotor.

' 5. In a refrigerator, an evaporator having pan compartments, a pan having dasher means therein and insertible in one of said compartments, 9. face plate adjacent one of said compartments, electromagnets carried by the face plate and provided with pole pieces, a pan insertible in one of said compartments, a rotor andpole pieces carried by the pan, said latter pole pieces being tromagnets, and inertia means for the rotor comprising gearing operatively connected with the rotor. Y

6. In a refrigerator, an evaporator having pan compartments, a face plate adjacent the end of said compartments, electromagnets carried by the face plate and provided with pole pieces, a pan insertible in one of said compartments, a rotor and pole pieces carried by the pan, said latter pole pieces adapted to engage with the pole pieces of the electromagnets, and inertia means for the rotor comprising interconnected dasher elements and gearing operatively connected with the rotor. v

7'. In a refrigerator, an evaporator having pan temperature selector means for modifying the operation of said control means, and means for manually adjusting said temperature selector to obtain a lower temperature at the evaporator and simultaneously rendering said motor elements operative while maintaining said control means in operation.

8. In a refrigerator, an evaporator having pan compartments, means for maintaining the evaporator within predetermined temperature limits,

control means for modifying the operation of said last named means to obtain subnormal cold conditions at the evaporator, a pan adapted to fit in one of said compartments, motor elements carried by the pan, dasher means in the pan'operativelyconnected with the motor elements, and a single manually adjustable member for simultaneously adjusting said control means and rendering the said motor elements operative while maintaining the control means in operation.

9. In a refrigerator, an evaporator having pan compartments, control means for maintaining the evaporator within predetermined temperature limits, a freezing pan insertible in one of said pan compartments, motor elements carried by the pan, dasher means operatively connected with said motor elements, temperature selector means for modifying the operation of said control means, and a common manually adjustable device for simultaneously adjusting the temperature selector and rendering said motor elements operative while maintaining said control means in operation.

10. A refrigerating system comprising in com- I bination, a cooling element including a freezing the cooling element andincluding motor actuated agitating means rendered operable coincident with the adjustment of the refrigerant medium circulatory mechanism to obtain a lower temperature.

ii. A refrigerating system comprising in combination, a cooling element including a freezing compartment, refrigerant medium circulatory mechanism adapted to be started and stopped at predetermined high and low temperature limits to maintain the cooling element at normal refrigerating temperatures and also to be started and stopped at a plurality of other high and low temperature limits to maintain the cooling element at varied temperature substantially below normal refrigerating temperatures to accelerate the freezing of ice cream mixtures, adjustable control means for starting and stopping said mechanism to maintain normal refrigerating temperatures at the cooling element, means for adjusting said control means to maintain at the cooling element accelerated ice cream mixture freezing temperatures. and an ice cream mixture freezing container adapted to fit in the freezing compartment of the cooling element, said container inciuilng motor actuated agitating means whereby the mixhaving freezing compartments, means for circulating a refrigerant through the evaporator, a control device for maintaining the evaporator within predetermined normal temperature limits and also maintaining the evaporator within predetermined variable temperature limits to obtain a subnormal temperature at the evaporator, a adapted to be fitted in any one of said compart ments, motor elements carried by said pan, and means for selectively setting said control device to obtain a predetermined subnorma'i tempera- ,ture and simultaneously closing the circuit to said motor elements while maintaining the said control device in operation.

14. In an electrical refrigerator, an evaporator having freezing compartments, means for circulating a refrigerant through the evaporator, a control device for selectively maintaining the evaporator within predetermind normal temperature limits and predetermined variable temperature limits to produce subnormal temperatures, a pan insertible in any one of said compartments, motor elements carried by said pan, means for simultaneously setting said control device to cause said means for circulating the refrigerant to operate to produce a subnormal temperature, said means being adapted in one position to close the circuit to said motor elements while maintaining the evaporator within predetermined variable low temperature limits and said means being also adapted to be moved to open the circuit to the motor elements. while still maintaining the control device in position to cause the refrigerator to operate within a sub-- normal temperature range. I

15 In a refrigerator, an evaporator having freezing compartments, circulating means for passing a refrigerant through theevaporator, an adjustable control device adapted to be selectively set manually to cause the operation of said circulating means to produce temperatures at the evaporator between predetermined high and low normal and predetermined high and low subnormal temperature limits, a freezing receptacle, agitating means therein, electrically driven motor elements carried by the receptacle to operatethe agitating means, and means associated with the control device to closea circuit to the electrically driven motor elements simultaneously with the adjustment of the control device to obtain sub normal temperatures at the evaporator while maintaining the control device effective to produce subnormal temperatures.

16. In a refrigerator, an evaporator having freezing compartments, circulating means for passing a refrigerant through the evaporator. an adjustable control device adapted to be'selectivelysetmsnualiytocausetheoperationofsaid circulating means to produce temperatures at the evaporator between predetermined high and low normal and predetermined high and low subnormal temperature limits, a freezing receptacle insertible in any one of said freezing compartments, agitating means therein electrically driven motor elements carried by the receptacle to operate the agitating means, and means associthe control device to obtain subiiormal tempera-. 'tures at the evaporator while maintaining the control device effective to produce subnormal temperatures.

CHARLES T. HOFFMAN. 

